As people who follow the local banking scene know, MainStreet Bank is in a very public battle with activist shareholders who threw down the gauntlet a few months ago.

Disgruntled shareholders Frank Williams Jr. and Kevin Keyes argued that the Fairfax-based bank is underperforming. They said they were rallying other shareholders for a proxy fight to shake up the board and management, and ultimately sell the bank, which has $270 million in assets and made a $134,000 first-quarter profit.

Among other things, Williams and Keyes take issue with the bank’s slow growth, low profits and depressed stock price. They argue shareholders would get better returns if the bank merged with a more competitive institution.

In a proxy contest, activists try to get shareholders to reject a company’s director nominees in favor of different nominees who will make changes at the company. This all comes to a head at the annual meeting, where shareholder votes are tallied.

MainStreet’s annual meeting is May 15. But Williams and Keyes didn’t have enough lead time to get competing director nominees on the proxy — a process that usually takes many months. Instead, they’re hoping that shareholders won’t vote at all.

“I’ve been told by a number of shareholders who said they will withhold their proxies as a show of dissatisfaction with the bank,” Williams told me.

He declined to say which shareholders or what portion of the proxies he expects will be withheld. (In February, he told me First Manhattan Co., the bank’s biggest shareholder with 10-some percent of shares, was in his corner.)

If more than two-thirds of shareholders don’t vote, the bank won’t have a quorum and would have to postpone the meeting. That’s a high bar that Williams acknowledges he likely won’t meet. But if a large number of shareholders do withhold, it would still send a message to management about the depth of shareholder discontent.

MainStreet Chairman and CEO Jeff Dick didn’t return my calls requesting comment for this story. But in his annual letter to shareholders, he made it pretty clear he was sticking to his guns on the bank’s conservative strategy.

“As other banks merge or sell, MainStreet will be here to pick up the pieces,” he wrote. “We may be the tortoise today, but that doesn’t mean we won’t finish the race strong and in good form.”